Brushes for a Delta 36-220 CMS...

[Bob Villa]

is point, has decent brushes but doesn't stop as it should. Folks have sugg ested new brushes and blowing out the sawdust. It would be nice if it was s afer to use...as new stuff tends to be made cheaper and doesn't last.

w instruction manual: "If (the brake will not function properly), turn the saw on and off four or five times. If the brake still does not stop the bla de in about 3 seconds, the problem may be worn brushes. Replace the brushes ...and try the saw again."

I have printed-out the manual for the 36-220, and there are no instructions for the brake problem.

[Norm Abram]

Yea, the show had to let you go because of your inability to measure in imperial units, the way God intended !

DIMENSIONS NEW ARE: 0.276" X 0.669" X 0.673"

Is this you from '09, Bob?

[Bob Villa]

Norm, are those measurements from the OEM brushes or the ones from eBay?

No, that wasn't me, but the information was useful. Thanks!

[clare]

Ans where does it say the original brushes are 0.276 inches?? And did the e-bay seller neasure with a micrometer, a caliper, a ruler, or a tape measure? They are listed as replacement brushes for Delta products including the model in question.

[Bob Villa]

Those measurements are the same as mine...thanks for that link!

[clare]

A bad switch, or the wrong switch, will cause the dynamic braking to fail. The switch has to short the motor wires when the power is removed, turning the motor into a generator working into a short circuit. Some have a diode and Capacitor in the "SHORT"

[Ed Pawlowski]

You may or may not be correct. If it comes down to scrapping the saw or risking $13 I'd give it a try.

Brushes are not NASA spec devices anyway.

[clare]

The "If (the brake will not function properly), turn the saw on and off four or five times" indicates the switch problem is a more common cause than the brushes.

[OFWW]

My apologies Bob, I assumed that when you said old saw and unavailable saw that you meant a table or radial arm saw. And that if the brushes were bad then it wouldn't run. Now you are speaking as if it does have a brake (newer) and it is possibly a sliding Compound saw.

So I jumped to conclusions that I shouldn't have. Perhaps the next time when you post you could include all this information up front?

At this point are you even sure you have a braking system on it?

[OFWW]

My apologies, I assumed you said old as in antiquity, and the parts were no longer available. Now you speak of a braking system, newer and so on.

Perhaps next time you could include all the missing info right up front?

[Bob Villa]

Title has all the info: Compound Miter Saw, and the model? Isn't 23 yrs old for a power tool?

[Brewster]

Bingo!

My Delta CMS had the same problem. The motor brake quit.

When the trigger is released, the brushes are effectively shorted by the switch to act as a brake. Cleaning the switch fixed it (for a while, grrrr...)

-BR

[Bob Villa]

Thanks, as far as I know, the switch is also obsolete!

[krw]

'93? Not particularly old, no. My RAS is almost 20 years older than that. I bought it new, so it's not like I buy antique tools.

[Markem]

Welcome to the troll go round, note the names.

[OFWW]

Now that I know what their braking system is, I would like to recommend this.

Take the motor off, take it to a motor shop for a cleanup, and have the armature dressed up and new brushes then installed.

Motor brushes by their nature eat into the armature and the brushes set the way they normally run. When the Motor operation is turned into a generator it is now operating on brushes with a partial seating.

It also could be a faulty diode, etc. but then the brake would never work once one of those components failed.

If you look at this picture the shiny copper portion is the armature, each section separated by mica and has a slight indentation, like a

1/16 th of an inch or so. Usually a saw blade can cut it down, the copper needs to be round, best done on a lathe.

Old guys with 6 volt generators and starters would know this as well as any electricians if they worked on their own cars.

Just wanted to pass a little on.

[Electric Comet]

ask norm he was the shop steward you will need to open your wallet

[Puckdropper]

Brewster wrote in news:nh7bsm$1c9a$ [e-mail]:

My Kobalt never did work properly. Reseating the brushes occasionally helps, but it still doesn't work every time. So maybe it's the switch?

If I play with the switch, the brake does activate. Even if I don't, though, it's a 15-30 second spin down so not too bad.

Puckdropper

[clare]

It's a lot newer than a lot of mine. For tools made in the eighties or before, 23 yerars is not old at all. It is "the prime of life". For most tools today, thinking about them in use 23 years from now is dilusional.

[clare]

A new switch, or a modification to use a sealed relay to control both power and braking - with the relay operated by the switch, will solve the problem over 90% of the time. That switch operates under extrreme conditions of dirt and vibration and is subject to atnmospheric conditions dust, sweat, dirt and oils that are very destructive - and the contacts NEED to handle not only the running current, the starting surges AND the brake current (which is often as high as or higher than the starting current)

Same problem on electric lawn mowers. The switch is the problem in the vast majority of cases - and the whole mlawnmower gets sent to the curb because of an inedequately designed switch.